Short answer- no.
Medium answer- rockbox development proceeds only at the pace implied by the
free time which volunteer developers are able to provide. There may be a
nano 5g port at some point in the future, but it will only happen when it
happens ('asking' for it won't/can't speed up development).
Longer answer- the ipod nanos (from second generation onwards) have a decent
amount of security measures implemented by Apple to make it hard to
circumvent the apple software and run 3rd-party code (e.g. rockbox). A small
handful of people are working to reverse-engineer this and have had success
with a number of newer Apple ipods, but as yet no success with the nano5g.
There is a wiki here, which I suggest you read:
http://www.freemyipod.org/wiki/Status